Ramzan Kadyrov, the Head of the Chechen Republic, responded on Tuesday to Musk’s tweet with a post on instant messaging and social media site Telegram, an English translation of which Musk later posted to his Twitter account.

In the post, Kadyrov dismissed Musk’s chances of winning any hypothetical showdown with Putin, calling him a “businessman and a Twitter user,” while describing Putin as a “world politician and strategist, who inspires awe in the West and in the U.S.”

Kadyrov mockingly invited the billionaire businessman to train for the fight in Chechnya and referred to him as a “gentle (effeminate)” person with the name “Elona.” Kadyrov suggested that Musk train in firearm use with “world championship special forces” at the Russian Special Forces University, who “beat U.S. special forces in 2015 like it was nothing.”

Kadyrov also suggested that Musk attend the Akhmat Fight Club, where he would be “trained to take a punch.” After the training program, he promised Musk would become “the brutal Elon you need to be.”

Musk’s tweet had already prompted a response from Kremlin official and head of Russian space agency Dmitry Rogozin, who called Musk a “little devil” and a “weakling.” Responding to Kadyrov on his Twitter, Musk kept the joke going, declining the invitation on the grounds that “such excellent training would give me too much of an advantage.”

Kadyrov is a known close ally of Putin, being the son and former military commander of Chechen President Akhmad Kadyrov, who pledged his allegiances to Russia in 2003 during the Second Chechen War. Putin invaded and conquered the tiny territory of Chechnya, located on Russia’s southern border with Georgia, over two wars waged in the late 1990s.

Since rising to power in 2007 following his father’s assassination, Kadyrov younger has been routinely condemned by the international community for human rights abuses. The Chechen leader has been accused of torturing enemies, arranging the assassination of journalist Anna Politkovyskaya, and kidnapping political rivals.

Putin has relied on Kadyrov for years to maintain stability in Chechnya, a region with a history of rebellion against Russia. In turn, Kadyrov has been entrusted with his own personal fiefdom, and has become one of the Russian president’s most loyal allies.

When Putin invaded Ukraine in February, Kadyrov wasted no time sending Chechen soldiers to assist his ally, and even urged Ukrainians to overthrow their own government.

Kadyrov might have sent his response to Musk from the battlefield, as a video recently posted on Telegram suggests that he was in Ukraine as of March 14, directly assisting the Russian war effort. The video’s accuracy has not been independently verified.

On Monday, Kadyrov used his Telegram account to demand the Ukrainian resistance movement surrender, “or you will be finished.”